""Soup of the evening, beautiful soup!"" sang Mock Turtle, to which Atlas (Vegetariana) here adds a vegetarian refrain. Recipes for more than 100 savory soups, chowders, bisques, purees and stews are adapted from several different world cuisines; suggested garnishes and basic nutrition analyses per serving are included. Following two introductory sections outlining stock and broth recipes with soup-making (and freezing) tips, chapters follow the seasons. Gingered Pumpkin-Apple Soup and Southwestern Fresh Corn Stew help usher in fall. The winter section mixes comforting old favorites such as Minestrone with new inventions like Italian Vegetable Stew with Gnocchi and zesty Taco Soup, with bulgur, pinto beans and chilies. Spring features Greek-Flavored Spinach and Orzo Soup, heady with lemon and fresh dill, and summer serves up Cool Ratatouille, a no-cook Creamy Avocado Soup (made with buttermilk instead of cream) and a sweetly refreshing Melon Medley. A final chapter, ""Accompaniments,"" adds recipes for muffins, breads, scones and dumplings--even croutons. Atlas's straightforward recipes, enlivened by quotes and drawings, promise soups of complex, rewarding flavor based on judicious combinations of ingredients rather than on complicated preparation. (Oct.)